your plants are wanting a shot of nitrogen , Give them what they want and they will repay you for it by giving you bigger and better bud . Try and keep your ph @6.5 . Cannabis needs N right up until 2 weeks before harvest , that is the time to cut the N out all together , I use a product called chempak no.3 low nitrogen , the npk of that is 12.5,25,25 , i only give them that when needed , maybe only 3-4 throughout the grow , My main ingreadients are Bio Bizz Bloom, seaweed extrcat,Superthrive and the magic mollasses